Barrier (FOSS)
Barrier is multiple computers one keyboard and mouse software. It switches one keyboard and one mouse between two or more computers. It is a software KM (keyboard-mouse) switch. I use it with my Linux Mint computer and my Windows 11 computer. You can share your clipboard between computers, too.
I can move my mouse and keyboard between the two (or more) of them with just a mouse pointer movement.
Since I have installed and run this on my Linux Mint computer and my Windows 11 computer, I will give you instructions on how to do that on those two computers. You could also run this on two Linux Mint computers, or two Windows computers, or even more computers. Barrier also runs on MacOS/OS X, FreeBSD, and OpenBSD.
These instructions assume that you have already installed Start Menu X on your Windows computers. I recommend that you do this first.
Install
Linux Mint
Click Menu –> Administration –> Software Manager. You will get a window something like the pic in the above left. In the upper-right of this window, type in barrier. You will see the picture in the above right. Choose Barrier, as highlighted. Click Install and continue to install the software.
Make sure that Barrier starts with Linux Mint. While running Barrier on Linux Mint, click the pull-down menu Barrier (upper left) > Change Settings > click to check the checkbox Start Barrier on startup > OK (lower right) > close window (upper right X). You can instead click the Linux Mint menu > Preferences (scroll down near the bottom) > Startup Applications (Cinnamon-settings) > + > Choose application > Barrier > Add application > close window (X in upper right).
Windows 11
Click the following link to get to the Download page. https://sourceforge.net/projects/barrier.mirror/
See the picture above. Then click Download. Your download should happen automatically.
Make sure that Barrier starts with Windows 11. While running Barrier on Windows 11, click Barrier > Change Settings > click checkbox Start Barrier on startup > OK > close window.
IP Address
You need to find out the IP Address for each of your computers. This is a little geeky, so I walk you through the process.
Linux Mint
Click Menu –> Preferences –> System Settings. Under Hardware, click Network. Look up the value for IPv4 Address. Write this down. Close the two windows.
Windows 11
Click Start Menu –> Control Panel –> Network and Sharing Center. Under View your basic network information and set up connections, find Connections:, and click the connection link after that. Click the Details… button. In the pop up window, look for IPv4 Address. Write it down. Close all three windows.
Start Barrier
Linux Mint
To run Barrier (for server or client), click Menu –> Accessories –> Barrier.
Windows 11
To run Barrier (for server or client), click Start Menu –> Barrier.
Configure
I have my the keyboard and mouse physically connected to my Linux Mint computer. This is the server. The keyboard and mouse are virtually connected to my Windows 11 computer over my network connection. Here are what the configuration windows look like on my computers.
Server
Remember, that your server computer is the one that has the keyboard and mouse physically connected to it.
Now, double-click the new monitor pic in that middle square. Name your screen and hit OK. Do the same for all of your other monitors (probably only one other). Click Start.
On your Server configuration window (mine above on left), click Configure Server…. The window below will appear, but will not have the two computers listed. Drag the monitor from the upper right to the center square. If you mess up, and place it somewhere else, just click the new monitor pic once, then hit the Delete key.
When you are finished, yours should look somewhat like the picture. The PowerEdge-T410 is my Linux Mint computer in the middle. The LAPTOP-UJLCQU18 is my Windows 11 computer on the right.
Client & Server
I found that in order to get Barrier to work, I had to disable SSL on both client and server. To do that, while in Barrier, press the F4 key on your keyboard. The Settings window will popup. Under Networking, unclick Enable SSL, then click OK. Do this on both the client computer and the server computer.
Also, make sure that the Screen name listed on the server software is the same as the name of the Screen name for the client computer. If this is incorrect, Barrier will now work.
Mouse Pointer
I sometimes have issues with the mouse working on the client computer, like when the anti-virus software pops up. I keep a second mouse attached directly to the client computer, but I keep the mouse out of the way, since I rarely need it.
I have found that sometimes the mouse pointer likes to jump back from the client monitor(s) to the server monitor. If you loose track of the mouse pointer, keep this in mind. This happens when:
- logging in
- double-clicking to install software
When moving the mouse to the other monitor, the mouse pointer gets stuck at the border of the server monitor, multiple times (usually three to five). I need to keep pushing the mouse pointer over. You might need to do this too.
Also, the mouse pointer will not traverse monitor-to-monitor if you have open a Start Menu or a pull-down menu open on the server monitor.
I find that when my antivirus program has a popup that Barrier stops working temporarily for that computer. You need to close the antivirus window with a mouse attached to that computer to fix.
My Barrier server (the computer that has the keyboard and mouse physically attached to it) runs Linux Mint. When the Linux Mint Menu is open, the mouse pointer will not leave that computer. Close the Menu to fix.
Troubleshoot
Only Run Once
Ensure that Barrier is not running more than one instance. When running, on both Linux Mint and Windows 11, you should see a Barrier icon on the taskbar in the lower-right. If Barrier is running more than once, you will see more than one icon. Shut down all but one instance of the program.
Barrier Needs Network Access
Barrier needs local network access, so if Barrier doesn’t work, then your network may be down. The mouse pointer will act slowly when you are downloading large files too.
If you have installed Portmaster on the same computer as your Barrier server, then Barrier will not work. You will need to change a setting for it to work. The setting is Global Settings > Privacy Filter > Connection Types > Force Block Incoming Connections – switch from on to off.
Additional Mouse
I like to have an additional mouse attached to each client as a backup. Sometimes that extra mouse is needed, like when antivirus software pops up on that computer. This can also be when the network/Internet is down. You’ll want the extra mouse to turn the network/Internet back on. I keep the extra mouse off on the side, since I usually don’t need it.
